DEMODECIC MANGE IN THE PIG.
This was well described for the first time by Csokor. It was afterwards seen by Neumann and Lindqvist.
The isolated pustules are of the size of a grain of sand, but when confluent may reach the size of a hazel-nut. They are sometimes dark in colour, often deep-seated, are surrounded by a zone of inflammation, and appear in places where the skin is fine (the groin, neck, belly, etc.). The demodex becomes lodged and multiplies, not in the hair follicles, but in the sebaceous glands. Csokor regarded this disease as contagious; in a herd of one hundred he found twenty-two pigs affected with it. Lindqvist, however, found but one case in a herd of two hundred.
NON-PSOROPTIC FORMS OF ACARIASIS.
These are produced in farm animals by arachnide belonging to the families of Trombidiidæ and Ixodidæ.
(1.) The Leptus autumnalis is considered to be the larva of the Trombidium Holoscriceum, or silky trombidion. It lives in late summer and autumn, in the grass.
Symptoms. The animals show intense itching, and cannot sleep owing to burning sensations. They continually rub themselves, and thus, secondarily, produce excoriated papules and patches resembling those of eczema. When the papules are very numerous, particularly if the animals are thin-skinned, more or less extensive erythema may be produced.
At the points attacked the skin swells, becomes red, and sometimes even violet, and exhibits irregular, isolated or confluent swellings, ¼ to ⅜ of an inch in diameter.
The parasite most commonly becomes fixed round the lips, the forehead, the cheeks, the sides of the neck, and the extremities.
The diagnosis is easy, the discovery of the parasite removing all doubt.